This invention relates generally to automotive safety restraint devices and, more particularly, to improved inflatable knee bolster module assemblies and associated methods such as may be useful in automotive safety restraint systems.
It is well known to protect a vehicle occupant using inflatable restraint systems which incorporate a cushion or bag, e.g., an xe2x80x9cairbag cushion,xe2x80x9d that is inflated or expanded with gas such as when the vehicle encounters a sudden deceleration, such as in the event of a collision. Such systems commonly comprise an inflatable airbag module stored behind the instrument panel of the vehicle. In such modules, the associated airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, such as in the event of a collision, the cushion begins to be inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as an xe2x80x9cinflator.xe2x80x9d This causes the airbag cushion to be deployed as a protective cushion for occupants within the vehicle passenger compartment.
As installed behind the vehicle instrument panel, the folded airbag cushion and the inflator device are typically contained within a module assembly reaction canister, which canister is commonly provided with a generally rectangular cover. The cover also comprises the cover or door for an airbag deployment opening that is formed in a portion of the instrument panel.
Automotive vehicles provided with inflatable airbag cushion safety restraint devices have commonly been designed with a stationary panel, located on a downward and forwardly inclined portion of the instrument panel, which panel acts as a knee crush zone. The portion of the instrument panel enclosed in the knee crush zone is oftentimes classified or referred to as a xe2x80x9cknee bolster.xe2x80x9d During a crash, momentum may cause the occupant to move forward and such that the legs of the occupant contact the knee bolster. As a result, such knee bolsters can desirably prevent the occupant from submarining beneath the inflated airbag. With such contact, the knee bolster may desirably deform under the load, absorbing energy and minimizing the forces acting on the legs of the occupant.
The use of a crushable stationary panel on the instrument panel of an automotive vehicle to provide a knee crush zone or bolster can be disadvantageous in a number of respects. For example, such a construction can serve to reduce the distance between the knees of an occupant and the instrument panel. Such a reduction may detract from and diminish the amount of leg room and the feeling of roominess the occupant would prefer to retain.
As a result, there has been a need and a demand for improved knee bolster assemblies.
At least partially in response to such need, airbag activated knee bolsters such as disclosed in commonly assigned Lang et al., U.S. Pat. No. 5,536,043, issued Jul. 16, 1996, and which patent disclosure is fully incorporated herein by reference, have been developed.
At least certain prior art inflatable knee bolster assemblies utilize retainer rings and a plurality of fasteners such as in the form of nuts, bolts or the like to attach the inflatable knee bolster cushion to either or both the associated knee bolster assembly module housing and the associated knee bolster panel or associated load distributor panel.
FIG. 1 illustrates a prior art knee bolster assembly, generally designated by the reference numeral 10 involving the attachment of a knee bag cushion 12 with an associated bolster panel 14 and an associated inflator 16, respectively.
With respect to the attachment of the knee bag cushion 12 with the bolster panel 14, the cushion 12 is secured between the bolster panel 14 and an associated bolster-side retainer plate or ring 20. In particular, the bolster panel 14 is provided with studs 22 which extend through the cushion 12 and through clearance holes 24 provided in the bolster-side retainer plate 20. Attachment nuts 26 are applied to the bolster panel studs 22, thereby clamping the cushion 12 between the bolster panel 14 and the bolster-side retainer ring 20.
With respect to the attachment of the knee bag cushion 12 with the inflator 16, the inflator 16 includes a circumferential attachment flange 30 to which is applied an annular reaction housing 32, also sometimes referred to as a xe2x80x9creaction plate.xe2x80x9d The cushion 12 is secured between the reaction plate 32 and an associated inflator-side retainer plate or ring 34 by means of studs 36 or the like, such as is known in the art and such as may extend from the retainer ring 34. For example, the rivets 36 can be sequentially passed through the cushion 12, the reaction plate 32 and the inflator attachment flange 30 and then secured with associated attachment nuts 40.
As will be appreciated, such attachment operations may be more difficult than desired as, for example, the bolster panel retainer plate 20 and the associated attachment nuts 26 are inside the cushion 12 and access to this interior region is through the relatively small inflator opening to the cushion. Further, the use of such multiple part fastening systems can be more complicated and costly than desired for efficient mass production.
FIG. 2 illustrates the assembly 10 of FIG. 1 after inflation of the cushion 12. As shown in FIG. 2, upon inflation of the cushion 12, large, generally triangular shaped voids 44 can occur or be formed between the cushion 12 and the bolster panel 14. As observed in previous tests, such an assembly can cause or result in undesired rotation of the bolster panel 14 relative to the retainer 20, for example, as signified by the arrows 46. As a result, the assembly 10 may experience or exhibit greater than desired instability.
The above-identified related application, now Schneider, U.S. Pat. No. 5,630,621, discloses a knee bolster assembly which advantageously overcomes at least some of the shortcomings or limitations of such earlier knee bolster assembly designs. The above-identified related application discloses a knee bolster assembly which advantageously eliminates the need for a bolster-side retainer and associated fasteners for attaching a bolster cushion to an associated bolster panel. In particular, it discloses attaching a bolster cushion to an associated bolster panel via the use of a rod and channel design. Further, as disclosed, such a knee bolster assembly can advantageously prevent the creation of undesirable voids which reduce assembly stability.
Certain limitations may, however, prevent or restrict the more widespread use of such knee bolster assemblies. For example, though such channels can generally be conveniently and economically formed via continuous extrusion processing, such processing generally necessitates that the channels have a continuous cross sectional form. As a result, contoured or other sweeping surface panel forms, such as may be desired to more closely fit or match vehicle interior trim sections may not be possible when using such extrusion processing. Also, a retainer ring and associated fasteners are employed to ensure a proper seal of the bolster cushion with the module housing, e.g., the reaction plate.
Thus, there is a continuing need and demand for further improved inflatable knee bolster module assembly and associated methods. In particular, there is a need and a demand for improved inflatable knee bolster module assemblies such that facilitate assembly and construction and such as may for readily permit contoured or other sweeping surface panel forms. Further, there is a need and a demand for such module assemblies and associated methods which are useful and effective in simplifying construction and assembly of associated inflatable knee cushions and reaction housings.
A general object of the invention is to provide an improved inflatable knee bolster module assembly and associated methods.
A more specific objective of the invention is to overcome one or more of the problems described above.
The general object of the invention can be attained, at least in part, in accordance with one preferred embodiment of the invention, through an inflatable knee bolster module assembly which includes an inflatable knee cushion having opposed first and second outer lateral sides. At least the first outer lateral side of the inflatable knee cushion includes at least first and second longitudinally spaced apart attachment extensions. The module assembly also includes a reaction housing joined with one of the first and second outer lateral sides of the inflatable knee cushion. The assembly also includes a load distributor panel joined with the other of the first and second outer lateral sides of the inflatable knee cushion. In accordance with such embodiment, the one of the reaction housing and the load distributor panel joined with the first outer lateral side includes at least first and second longitudinally spaced apart attachment openings respectively corresponding to the first and second longitudinally spaced apart attachment extensions of the inflatable knee cushion. In the module assembly, the first attachment extension extends through the first attachment opening in secured relationship and the second attachment extension extends through the second attachment opening in secured relationship.
In one particular form of such a module assembly, at least the first longitudinally spaced apart attachment extension of the inflatable knee cushion is in the form of a material loop and the module assembly additionally includes a retention rod extendable through the material loop attachment extension to prevent withdrawal of the material loop attachment extension through the first attachment opening.
In another particular form of such a module assembly, at least the first longitudinally spaced apart attachment extension of the inflatable knee cushion forms a slot and the at least the one of the reaction housing and the load distributor panel joined with the first outer lateral side additionally includes an attachment projection extending therefrom in a direction opposite the inflatable knee cushion, with the attachment projection extendable through the attachment extension slot.
The prior art generally fails to provide inflatable knee bolster module assemblies and associated methods such that facilitate assembly and construction to an extent as great as generally desired. Further, the prior art generally fails to provide inflatable knee bolster module assemblies and associated methods which as readily permit or are otherwise conducive to use with or in conjunction with contoured or other sweeping surface panel forms such as may be desired to provide a better match or fit with the vehicle interior trim. Still further, the prior art generally fails to provide module assemblies and associated methods which are as useful and effective as desired in simplifying construction and assembly of associated inflatable knee cushions and reaction housings.
The invention further comprehends an improvement in an inflatable knee bolster module assembly which includes an inflatable knee cushion having opposed first and second outer lateral sides, a first panel member comprising a reaction housing panel and a second panel member comprising a load distributor panel. In accordance with one particular embodiment of the invention, the improvement includes at least the first outer lateral side of the inflatable knee cushion having at least first and second longitudinally spaced apart attachment extensions. The improvement also includes at least one of the first and second panel members having at least first and second longitudinally spaced apart attachment openings respectively corresponding to the first and second longitudinally spaced apart attachment extension of the inflatable knee cushion with the first attachment extension extending through the first attachment opening in secured relationship and the second attachment extension extending through the second attachment opening in secured relationship.
The invention still further comprehends a method for attaching an inflatable knee cushion with at least one panel member selected from the group of a reaction housing panel and a load distributor panel in an inflatable knee bolster module assembly. The method involves passing first and second longitudinally spaced apart attachment extensions of a first outer lateral side of the inflatable knee cushion through, respectively corresponding first and second attachment openings in the at least one panel member, in secured relationship.
Other objects and advantages will be apparent to those skilled in the art from the following detailed description taken in conjunction with the appended claims and drawings.